Heterogeneity in the Distribution of Mitochondrial DNA Haplotypes in Female Rainbow Trout Spawning in Different Seasons

1994 ◽  
Vol 51 (S1) ◽  
pp. 284-289 ◽  
Author(s):  
Roy G. Danzmann ◽  
Moira M. Ferguson ◽  
David M. Heculuck
Keyword(s):  
Mitochondrial Dna ◽  
Significant Heterogeneity ◽  
Temporal Heterogeneity ◽  
Commercial Fish ◽  
Mtdna Haplotypes ◽  
Hatchery Stock ◽  
Different Seasons ◽  
Spawning Time ◽  
The Government ◽  
Mtdna Haplotype

Analysis of females spawning throughout the year (October to late February) at a commercial fish farm in Ontario, revealed significant heterogeneity in the distribution of their mitochondrial DNA (mtDNA) haplotypes. These findings are consistent with previous data from this stock and indicate that female– daughter spawning times are temporally stable. This suggests a high maternal genetic contribution to this trait. Conversely, no temporal heterogeneity in the spawning times of females with different mtDNA haplotypes was observed in an unselected government (Ontario Ministry of Natural Resources) hatchery stock recently derived from a wild naturalized population. The government hatchery stock is normally spring spawning and has much higher levels of nucleon diversity compared with the cultured stock. Therefore, it appears that only a limited number of family lines within unselected stocks may show the propensity towards greatly accelerated spawning times. Furthermore, associations between spawning time and mtDNA haplotype may only become apparent following several generations of artificial selection.

Mitochondrial DNA Diversity and Population Structure in Marine Fish Species from the Gulf of Mexico

1994 ◽  
Vol 51 (S1) ◽  
pp. 205-214 ◽  
Author(s):  
John R. Gold ◽  
Linda R. Richardson ◽  
Carol Furman ◽  
Feng Sun
Keyword(s):  
Mitochondrial Dna ◽  
Gulf Of Mexico ◽  
Isolation By Distance ◽  
Red Drum ◽  
Red Snapper ◽  
Maximum Parsimony Analysis ◽  
Female Population ◽  
Mtdna Haplotypes ◽  
Haplotype Frequencies ◽  
Mtdna Haplotype

Variation in mitochondrial DNA (mtDNA) was examined among 693 red drum (Sciaenops ocellatus), 300 black drum (Pogonias cromis), and 421 red snapper (Lutjanus campechanus) sampled from several localities in the Gulf of Mexico. The number of mtDNA genotypes (haplotypes) observed were: 99 in red drum, 37 in black drum, and 68 in red snapper. Variation in mtDNA haplotype frequencies among localities in all three species was not significant, although two mtDNA haplotypes in black drum appeared to be clinally distributed. Maximum-parsimony analysis and phenetic clustering of mtDNA haplotypes and of samples in each species revealed little evidence of phylogeographic structuring. These data indicate that gene flow among localities in each species is sufficient to preclude genetic divergence. Spatial autocorrelation analysis of mtDNA haplotype frequencies revealed an isolation-by-distance effect in red drum and black drum, and indicated that migration between neighboring estuaries or bays in black drum may be less frequent than in red drum. Spatial autocorrelations in red snapper were negative in all distance classes, suggesting little migration even between adjacent localities. Differences in intrapopulational mtDNA diversities were found in all three species, suggesting that geographic differences in effective female population size may occur within each species.

Proximate Analysis of British Columbia Herring in Relation to Season and Condition Factor

1939 ◽  
Vol 4b (5) ◽  
pp. 478-490
Author(s):  
John Lawson Hart ◽  
Albert L. Tester ◽  
Desmond Beall ◽  
John P. Tully
Keyword(s):  
British Columbia ◽  
Oil Content ◽  
Condition Factor ◽  
Calorific Value ◽  
Proximate Analysis ◽  
Early Spring ◽  
Different Seasons ◽  
Spawning Time ◽  
Average Condition ◽  
The Individual

Analysis by standard methods of samples of Clupea pallasii from different seasons and localities in British Columbia showed the following ranges in composition: water, 64.2 to 80.2%; oil, 4.1 to 19.4%; protein, 10.1 to 16.8%; ash, 1.9 to 2.8%. Oil content is highest in summer, declines during the fall and winter, and falls to a minimum after spawning time in early spring. There is an accompanying decline in the weight of the fish. Herring are highly variable in calorific value (2.41 to 0.94 Calories per gram). Potential oil yields on reduction as high as 30 gallons per ton are indicated with a minimum of 7 gallons per ton. Average condition factors for samples were determined by averaging the individual condition factors obtained from [Formula: see text], when C is the condition factor, W is weight in grams, L is length in millimetres, and 3.26 is the exponent in the empirically fitted equation W = CLn. This condition factor was found to be positively correlated with oil content and to follow in general the same seasonal trend.

Comparison of Allozyme and Mitochondrial DNA Variation in Populations of Walleye, Stizostedion vitreum

1989 ◽  
Vol 46 (12) ◽  
pp. 2074-2084 ◽  
Author(s):  
Robert D. Ward ◽  
Neil Billington ◽  
Paul D. N. Hebert
Keyword(s):  
Mitochondrial Dna ◽  
Glacial Refugia ◽  
Divergence Times ◽  
Stizostedion Vitreum ◽  
Dna Variation ◽  
Mtdna Variation ◽  
Mtdna Haplotypes ◽  
Total Genetic Diversity ◽  
Allozyme Loci ◽  
Organelle Genes

Twelve populations of walleye (Stizostedion vitreum) from the Great Lakes and three populations from northern Manitoba were screened for allozyme and mitochondrial DNA (mtDNA) variation. Nine enzyme loci known to show genetic variation were screened in all fish: five of them (Prot-4, Prot-2, Mdh-3, Idh-1, Adh) showed appreciable polymorphism. MtDNA was examined in all fish using six endonucleases that detected polymorphic sites and a further 13 endonucleases that detected only monomorphic sites. Only one of the allozyme loci (Prot-4) showed evidence of geographic patterning of allele frequencies. By contrast, the mtDNA haplotypes showed clear geographic variation. The proportion of total genetic diversity attributable to population differentiation (Gst) was three to five times greater for mtDNA than for the allozymes. Gst values for organelle genes are expected on theoretical grounds to be greater than for nuclear genes, and this expected difference may be enhanced in walleye because of the likelihood that, in this species, male-mediated gene flow exceeds that of females. The distributions of mtDNA haplotypes and estimated divergence times are consistent with the derivation of extant walleye populations from three different glacial refugia.

scholarly journals Evidence for non-neutrality of mitochondrial DNA haplotypes in Drosophila pseudoobscura.

Genetics ◽  
1988 ◽  
Vol 120 (2) ◽  
pp. 485-494
Author(s):  
A F MacRae ◽  
W W Anderson
Keyword(s):  
Mitochondrial Dna ◽  
Nuclear Genome ◽  
Drosophila Pseudoobscura ◽  
Initial Population ◽  
Mitochondrial Haplotypes ◽  
Mtdna Haplotypes ◽  
Selective Neutrality ◽  
Frequency Changes ◽  
Apparent Equilibrium ◽  
Neutral Markers

Abstract Mitochondrial DNA (mtDNA) haplotypes usually are assumed to be neutral, unselected markers of evolving female lineages. This assumption was tested by monitoring haplotype frequencies in 12 experimental populations of Drosophila pseudoobscura which were polymorphic for mtDNA haplotypes. Populations were maintained for at least 10 generations, and in one case for 32 generations, while tests of mtDNA selective neutrality were conducted. In an initial population, formed from a mixture of two strains with different mitochondrial haplotypes, the frequency of the Bogota haplotype increased 46% in 3 generations, reaching an apparent equilibrium frequency of 82% after 32 generations. Perturbation of this equilibrium by addition of the less common haplotype resulted in a rapid, dramatic increase in frequency of the second haplotype, and a return to essentially the same equilibrium frequency as before perturbation. This behavior is not consistent with mtDNA neutrality, nor is the equilibrium consistent with a simple model of constant selection on the haploid mtDNAs. Replicate cage experiments with mtDNA haplotypes did not always generate the same result as the initial cage. Several lines of evidence, including manipulations of the nuclear genome, support the idea that both nuclear and mitochondrial genomes are involved in the dramatic mtDNA frequency changes. In another experiment, strong female viability selection was implicated via mtDNA frequency changes. Although the causes of the dramatic mtDNA frequency changes in our populations are not obvious, it is clear that Drosophila mitochondrial haplotypes are not always simply neutral markers. Our findings are relevant to the introduction of a novel mtDNA variant from one species or one population into another. Such introductions could be strongly favored by selection, even if it is sporadic.

scholarly journals Monitoring of fish diseases in the Magadan region

2021 ◽  
Vol 36 ◽  
pp. 07008
Author(s):  
E.A. Vitomskova
Keyword(s):  
Pacific Salmon ◽  
Animal Health ◽  
Natural Populations ◽  
Clinical Signs ◽  
Commercial Fish ◽  
Fish Diseases ◽  
North East ◽  
Comparative Aspect ◽  
Different Seasons

In such a large region as the Far North-East of Russia, there is still no purposeful ichthyopathological study of fish diseases, which has epizootic and epidemiological significance. The material for the study was commercial fish caught in different seasons of 1995-2021. As a result of the research, individuals of natural populations and in aquaculture with clinical signs of infectious and parasitic diseases were found, and cultures of virulent strains of microorganisms were isolated. According to the results of the parasitological study, larvae of nematodes of the family Anisakidae and plerocercoids of cestodes Diphyllobothriidae, which have important epidemiological and epizootic significance, were registered. Based on long-term ichthyopathological studies, a retrospective review of own data was carried out. The analysis of infectious diseases of mature individuals of anadromous Pacific salmon of the genus Oncorhynchus, as well as long-term parasitological monitoring in a comparative aspect of the invasion of commercial fish by helminths dangerous to human and animal health, is presented.

Consumer preference and demand for traceable food attributes

2016 ◽  
Vol 118 (9) ◽  
pp. 2140-2156 ◽  
Author(s):  
Jiao Lu ◽  
Linhai Wu ◽  
Shuxian Wang ◽  
Lingling Xu
Keyword(s):  
Consumer Preferences ◽  
Consumer Preference ◽  
Multinomial Logit Model ◽  
Chinese Government ◽  
Significant Heterogeneity ◽  
Content Type ◽  
Food Traceability ◽  
Traceability System ◽  
Chinese Consumer ◽  
The Government

Purpose The purpose of this paper with pork as a case is to analyze Chinese consumer preference and demand for traceable food attributes, in order to provide a useful reference for Chinese Government in developing the safe food market and preventing food safety risks. Design/methodology/approach This research surveyed 1,380 consumers in seven pilot cities that designated by the Chinese Ministry of Commerce for the construction of a meat and vegetable circulation traceability system. A choice-based conjoint analysis and multinomial logit model were used to study consumer preferences and demand for traceable pork attributes. Findings The results demonstrated that certification of traceable information was the most important characteristic, followed by appearance and traceable information. Significant heterogeneity was obtained in consumer preferences for the attributes of traceable pork. Also, consumers’ preferences for traceable attributes were memorably influenced by age, education level, and income level. Social implications Based on these results, the government should encourage and support the production of traceable food with different certification types and different traceability levels. Meanwhile, the development of food traceability systems should be combined with a quality certification labeling system. Originality/value This study extends the applicability of the setting of traceable food attributes and levels in China, and it will improve Chinese food traceability systems through multilateral cooperation.

Genetic Relationships Among Chum Salmon Populations in Southeast Alaska and Northern British Columbia

1994 ◽  
Vol 51 (S1) ◽  
pp. 50-64 ◽  
Author(s):  
C. M. Kondzela ◽  
C. M. Guthrie ◽  
S. L. Hawkins ◽  
C. d. Russell ◽  
J. H. Helle ◽  
...  
Keyword(s):  
British Columbia ◽  
Chum Salmon ◽  
Genetic Relationships ◽  
The United States ◽  
Oncorhynchus Keta ◽  
Significant Heterogeneity ◽  
Southeast Alaska ◽  
Queen Charlotte Islands ◽  
Spawning Time ◽  
Mixed Stock

Allozymes from 46 loci were analyzed from chum salmon (Oncorhynchus keta) collected at 61 locations in southeast Alaska and northern British Columbia. Of the 42 variable loci, 21 had a common allele frequency <0.95. We observed significant heterogeneity within and among six regional groups: central southeast Alaska, Prince of Wales Island area, southern southeast Alaska – northern British Columbia, north-central British Columbia, and two groups in the Queen Charlotte Islands. Genetic variation among regions was significantly greater than within regions. The three island groups were distinct from each other and from the mainland populations. Allele frequencies were stable over time in 14 of 15 locations sampled for more than 1 yr. The geographic basis for heterogeneity among regions is confounded in part by spawning-time differences. The Prince of Wales and Queen Charlotte populations spawn in the fall; the mainland populations spawn mainly in the summer, although some overlap exists. Overall, most genetic diversity (97%) occurred within sampling locations; the remaining diversity was distributed almost equally within and among regions. Our genetic data may provide fishery managers a means to estimate stock composition in the mixed-stock fisheries near this boundary between the United States and Canada.

scholarly journals Individual Treatment Effects of Budget Balance Rules

2020 ◽  
Vol 20 (274) ◽  
Author(s):  
Francesca Caselli ◽  
Daniel Stoehlker ◽  
Philippe Wingender
Keyword(s):  
Treatment Effects ◽  
National Level ◽  
Specific Treatment ◽  
Average Treatment Effect ◽  
Fiscal Rules ◽  
Individual Treatment ◽  
Significant Heterogeneity ◽  
Budget Balance ◽  
The Government ◽  
Country Specific

This paper investigates the heterogenous effects of budget balance rules on fiscal policy in a large sample of countries. To derive country-specific treatment effects of fiscal rules and conduct inference, we use a Synthetic Difference-in-Differences Method. Our results indicate that countries with a budget balance rule improve their fiscal balance on average by around 3 percent after its introduction. However, our results also illustrate the importance of going beyond the average treatment effect, as it masks significant heterogeneity in the country-specific impact of the rule. We find that countries that would have had large deficits in the absence of the fiscal rule exhibit positive treatment effects, thus reducing their budget deficits. On the other hand, countries with budget surpluses respond to fiscal rules by reducing their budget surplus and moving closer to the numerical target of the rule. Our results also suggest that rules’ design matters: a small overall number of fiscal rules, and the presence of a monitoring process outside the government, especially at the supra-national level, improve significantly the effectiveness of the rules.

scholarly journals A pedigree-based analysis of mitochondrial DNA diversity in a dog population on the example of German Hovawarts

2015 ◽  
Vol 58 (2) ◽  
pp. 335-342
Author(s):  
S. Zielińska ◽  
I. Głażewska
Keyword(s):  
Mitochondrial Dna ◽  
Pedigree Analysis ◽  
Mtdna Mutations ◽  
Dna Diversity ◽  
Mtdna Inheritance ◽  
Mtdna Haplotypes ◽  
History Of ◽  
Pedigree Errors ◽  
Mtdna Diversity ◽  
New Mutations

Abstract. The purpose of the article is to illustrate the use of pedigree analysis to evaluate mtDNA diversity in a selected population of pedigree dogs, to describe the paths of mtDNA inheritance and to estimate the spread of potential pedigree errors or mutations that occurred in different generations of ancestors. Hovawart, old German breed, was used as an example. The number and frequencies of mtDNA haplotypes were calculated based on numbers of dam lines and their representatives. The scale of potential errors in calculations that can result from pedigree errors or from new mutations in ancestors from the 5th or 10th ancestral generation was evaluated. The analysis included 368 breeding bitches from four German kennel organizations. The bitches represented three dam lines, with the Ho1, Ho2 and HoU mtDNA haplotypes. Significant differences in the frequency of the haplotypes in the population, from 0.27 to 73.37 %, and among kennel organizations and regions of the country were recorded. Considerable differences in the scale of potential errors in calculations arising from mtDNA mutations or pedigree errors were noted between 0.27 and 28.69 %, depending on the number of representatives of the subline in which the error appeared and the generation taken into account in the simulations. The study revealed an interesting paradox: although the differences between the haplotypes are the result of events (mutations) from thousands of years ago, the number and the frequencies of the haplotypes in the population are the result of the modern history of the population and current breeding policy.

Population structure, gene flow, and historical demography of a small coastal shark (Carcharhinus isodon) in US waters of the Western Atlantic Ocean

2016 ◽  
Vol 73 (9) ◽  
pp. 2322-2332 ◽  
Author(s):  
David S. Portnoy ◽  
Christopher M. Hollenbeck ◽  
Dana M. Bethea ◽  
Bryan S. Frazier ◽  
Jim Gelsleichter ◽  
...  
Keyword(s):  
Population Structure ◽  
Gene Flow ◽  
Significant Heterogeneity ◽  
Demographic Model ◽  
Western Atlantic ◽  
Nursery Areas ◽  
Seasonal Movement ◽  
Southeastern Us ◽  
Mtdna Haplotypes ◽  
Approximate Bayesian

AbstractPatterns of population structure, genetic demographics, and gene flow in the small coastal shark Carcharhinus isodon (finetooth shark) sampled from two discrete nurseries along the southeastern US coast (Atlantic) and three nurseries in the northern Gulf of Mexico (Gulf), were assessed using 16 nuclear-encoded microsatellites and 1077 base pairs of the mitochondrial DNA (mtDNA) control region. Significant heterogeneity in microsatellite allele distributions was detected among all localities except between the two in the Atlantic. Significant heterogeneity in mtDNA haplotypes was not detected, a result likely due to extremely low mtDNA diversity. The genetic discontinuities combined with seasonal movement patterns, a patchy distribution of appropriate nursery habitat, the apparent absence of sex-biased gene flow, and the occurrence of mating in the vicinity of nursery areas, suggest that both male and female finetooth sharks display regional philopatry to discrete nursery areas. Global and local tests of neutrality, using mtDNA haplotypes, and demographic model testing, using Approximate Bayesian Computation of microsatellite alleles, supported a range-wide expansion of finetooth sharks into US waters occurring less than ∼9000 years ago. These findings add to the growing number of studies in a variety of coastally distributed marine fishes documenting significant barriers to gene flow around peninsular Florida and in the eastern Gulf. The findings also provide further evidence that the traditional model of behavioural ecology, based on large coastal sharks, may not be appropriate for understanding and conserving small coastal sharks.

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